Contaminant-reactive geocomposite mat and method of manufacture and use

Abstract

Reactive geocomposite mats, and their method of manufacture, for treating contaminants in soil or water that allow the passage of essentially non-contaminated water therethrough. The geocomposite mat includes a pre-formed woven or non-woven geotextile, having a thickness of about 6 mm to about 200 mm, and having, a porosity sufficient to receive a powdered or granular contaminant-reactive material, contaminant-sorptive material, or a contaminant-neutralizing material (hereinafter collectively referred to as “contaminant-reactant material” or “contaminant-reactive material”) throughout its thickness, or in any portion of the thickness across its entire major surface(s). The powdered or granular contaminant-reactive material is disposed within the pores of the previously formed, high loft geotextile mat to surround the fibers, e.g., by vacuum or vibrating the high loft mat while in contact with the contaminant-reactive material to allow the powdered or granular contaminant-reactive material to flow by gravity into the pores of the previously formed geotextile and vibrational forces. Liquid-permeable cover sheets are adhered to the upper and lower major surfaces of the filled geotextile to prevent the powdered or granular material from escaping from the geotextile during transportation and installation.

1. A method of manufacturing a water-permeable geocomposite article capable of sorbing, reacting with, or neutralizing a liquid-contained contaminant and allowing the passage of non-contaminated water therethrough comprising:
 providing a pre-formed geotextile mat having an apparent opening size in the range of about 0.5 mm to about 6 mm and having opposed major surfaces; 
 contacting one of the major surfaces of the geotextile mat with a powdered or granular organophilic clay capable of sorbing, reacting with, or neutralizing the liquid-contained contaminant, and causing the powdered or granular organophilic clay to flow into the pre-formed geotextile mat to fill at least a portion of the pre-formed geotextile mat within openings of the mat, wherein the powdered or granular reactive material does not prevent the flow of water through the geocomposite article; and 
 adhering a liquid-permeable cover sheet to a major surface of the pre-formed geotextile mat by needle-punching or heat sealing the cover sheet to the pre-formed geotextile mat after the mat has received the powdered or granular organophilic clay. 
 
     
     
       2. The method of  claim 1  further including the step of securing another liquid-permeable cover sheet to a lower major surface of the geotextile mat before filling at least a major portion of the pre-formed geotextile mat with the powdered or granular organophilic clay. 
     
     
       3. The method of  claim 1 , further including the step of covering edges of the pre-formed geotextile mat with a sheet material layer. 
     
     
       4. The method of  claim 3 , wherein the edges of the geotextile mat are covered with excess material from one or both of the cover sheets. 
     
     
       5. The method of  claim 4  wherein the excess material of the cover sheets are secured together to cover the edges of the geotextile mat by adhesively securing the cover sheets together over the edges of the geotextile, or heat-sealing the cover sheets together surrounding the edges of the geotextile. 
     
     
       6. The method of  claim 1 , wherein the powdered or granular organophilic clay is caused to flow into the geotextile mat by vibrating the geotextile mat while in contact with the powdered or granular organophilic clay. 
     
     
       7. The method of  claim 1 , wherein the powdered or granular organophilic clay is caused to flow into the geotextile by applying a vacuum to an undersurface of the geotextile to draw the powdered or granular organophilic clay into the mat from an upper surface. 
     
     
       8. The method of  claim 2  further including the step of providing at least one of the cover sheets having a dimension larger than the major surface of the geotextile mat to provide excess cover material so that the excess cover material extends over an edge surface of the geocomposite article, and securing the excess cover material to the geotextile article to cover the edge surface, thereby reducing or eliminating escape of powdered or granular organophilic clay through the covered edge surface of the geotextile article. 
     
     
       9. The method of  claim 8 , including the step of covering all edge surfaces with excess cover material, and securing the excess cover material to the geocomposite article thereby reducing or eliminating escape of powdered or granular organophilic clay through all edge surfaces of the geotextile article. 
     
     
       10. The method of  claim 8 , wherein the cover sheet is secured over the edge surface by an expedient selected from the group consisting of adhesively securing, needlepunching and ultrasonic welding. 
     
     
       11. The method of  claim 9 , wherein at least one of the cover sheets is secured over all edge surfaces by an expedient selected from the group consisting of adhesively securing, needlepunching and ultrasonic welding. 
     
     
       12. A method of manufacturing a water-permeable multi-layer geocomposite article capable of sorbing, reacting with, or neutralizing a liquid-contained contaminant, said geocomposite article having a geotextile layer containing a powdered or granular organophilic clay adhered to an adjacent geotextile mat by needle-punching or heat sealing, said geocomposite article allowing the passage of essentially non-contaminated water therethrough, the method comprising:
 providing a pre-formed geotextile mat having an apparent opening size in the range of about 0.5 mm to about 6 mm and having opposed major surfaces; 
 contacting one of the major surfaces of the geotextile mat with a powdered or granular organophilic clay capable of sorbing, reacting with, or neutralizing a liquid-contained contaminant, and causing a portion of the powdered or granular organophilic clay to flow into the pre-formed geotextile mat to fill at least a portion of void spaces in the pre-formed geotextile mat, wherein the powdered or granular reactive material does not prevent the flow of water through the geocomposite article; 
 heat-adhering a liquid-permeable cover sheet to the pre-formed geotextile mat after the mat has received the powdered or granular organophilic clay. 
 
     
     
       13. The method of  claim 12 , wherein the liquid-permeable cover sheet has an apparent opening size in the range of about 0.5 mm to about 6 mm, and is at least partially filled with powdered or granular organophilic clay after adhering the liquid-permeable cover sheet to the at least partially filled first geotextile layer. 
     
     
       14. The method of  claim 1 , wherein the powdered or granular organophilic clay disposed within the void spaces of the geotextile mat includes 0 to 10 lb/ft 3  of a sodium bentonite. 
     
     
       15. The method of  claim 2 , wherein the geotextile fibers are selected from the group consisting of polyolefin, polyester, polyamide, and copolymers of any two or more of the foregoing. 
     
     
       16. The method of  claim 12 , wherein the powdered or granular reactive organophilic clay has a particle size such that at least 90% of the particles have a size in the range of about 6 mesh to about 325 mesh. 
     
     
       17. The method of  claim 1 , wherein the geocomposite article has 30 lb/ft 3  to 100 lb/ft 3  of powdered or granular reactive organophilic clay contained therein. 
     
     
       18. The method of  claim 12 , wherein the geotextile fibers are selected from the group consisting of polyethylene fibers, polypropylene fibers, polyester fibers and polyamide fibers. 
     
     
       19. The method of  claim 1 , wherein the pre-formed geotextile mat is non-woven.